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Thread: Low octane to high octane tables . How long for switch

  1. #1
    Tuner in Training
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    Feb 2013
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    Low octane to high octane tables . How long for switch

    Can someone direct me to how the computer switches ?

    I was told by a tuner that the high octane table is used at first but if the ecu sees knock it will switch to the low octane and be kind of locked there till 20-25 key ons ?

    Anyone have a link to explain this or can explain to me

  2. #2
    Tuning Addict 5FDP's Avatar
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    May 2012
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    Rogers, MN
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    Log the channel called knock learn factor. That will tell you exactly what it is doing.

    The channel either goes 1 to 0 or 0 to 1 depending on what vehicle/computer it is. So for example if it starts at 1 then you get a bunch of knock, it will work it's way down to 0. If the high octane table was at 20 degrees and the low octane at 14 degrees, then at .50 KLF it should be asking for ~17 degrees.

    The less that it knocks the faster it works it way back to only the high octane table. It has nothing to do with key cycles.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner in Training
    Join Date
    Feb 2013
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    Thanks I will do this !